Gas Boiler Replacement: Prepare For The Future
Getting a new boiler is an experience most homeowners will encounter. Whether you’re looking for a boiler right now or you’re preparing for the future, we understand that finding a gas boiler replacement is a stressful, yet worthwhile investment. By swapping to a new boiler, your home energy can operate at 94% efficiency on average.
Finding the right replacement boiler requires preparation and research. And that process starts with understanding what the best new boiler system will be for you both now and in the future. Replacing your current boiler is also a great opportunity to get a new heating system that is more efficient and sustainable.
Your new boiler replacement will help heat your home for the next 15 years. Anticipating your future needs may be a difficult task but, with a Gas Safe engineer, you can ease the burden. If you want to find a Gas Safe registered engineer that can supply and safely install your boiler, we can help you.
With our help, you can find and compare up to 4 quotes with no cost and nor obligation so that you can choose the best price that fits your individual needs. Just click the button below to find installers near you.
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Learn More in Our Guide
- Why Should You Replace Your Boiler?
- When Is It Time To Replace Your Boiler?
- How Much Does A New Boiler Cost In The Uk?
- What Are The Installation Costs For A Boiler Replacement?
- Is There A Government Grant Which Encourages Green Homes?
- 5 Reasons Why Gas Boiler Replacement Is Future Proof
- Find Local Engineers For Boiler Replacements
- FAQ
In 2021, the UK government announced its Heat and Building Strategy that involves a two-phase change toward banning gas boilers:
- ✔ By 2025: gas boilers will be banned in newly constructed houses
- ✔ By 2035: gas boilers can no longer be installed in existing properties
The announcement comes after annual research showing that 14% of UK emissions come from domestic energy use. It is expected that there will be a phase-out of the sale of new boilers by 2035 in favour of low-carbon heating systems, such as heat pumps and biomass boilers. Keep in mind that there is news that states that the start of the ban can be extended.
Why Should You Replace Your Boiler?
Engineers recommend it's time to get a replacement boiler when your current boiler becomes either damaged, stops working, or works less efficiently. Naturally, as boilers do a lot of the heavy lifting to keep our homes warm, it’s important and safe that they be replaced regularly. But you may also want to replace your gas or oil boiler to be more sustainable.
Getting a new boiler is not only beneficial for your home comfort, but also for your wallet. On average, 60% of your annual home energy bill goes towards heating your home. If your home is operating with a boiler that is old and less energy-efficient, you could be wasting £30 for every £100 spent on your energy bill.
Replacing your boiler may have a high upfront cost, but if you upgrade to a more efficient solution, you will be paying it off in no time.
When Is It Time To Replace Your Boiler?
The average lifespan of a new boiler system is 10-15 years. However, it may be important to start thinking about boiler replacements earlier. There are some signs that your boiler needs to be replaced. We have listed the main signs for you here:
1. Your boiler is older than 15 years
If well-maintained, a boiler can last beyond 15 years. However, it doesn’t mean that you should always continue using it for that long. As boilers age, they will run less efficiently as more gas escapes through the gas flue.
Boilers over 10 years old can already lose up to 30% of their efficiency. Nowadays, modern boilers are government regulated to be more than 90% efficient. This means that almost all of the fuel consumed is turned into energy for your home.
Also, as your boiler gets older, you may encounter more difficulty finding replacement parts for your boiler. Non-essential parts (e.g. body casing) tend to be discontinued by manufacturers early on. While mechanical and electrical components (e.g. gas valves) tend to be manufactured for the next 10 years.
2. Your energy bills are higher than usual
If you notice an unusually high reading or bill it might be indicative of your boiler not operating at full capacity. It will use much more energy to attain its maximum efficiency. Having an older, low energy-rated boiler is a likely explanation and a reason to get a replacement boiler because you’re potentially wasting fuel, money, and producing excess carbon emissions.
Therefore, if you’re considering getting a replacement gas boiler, it might be best to consider switching to low-carbon heating options (e.g. heat pumps, biomass boilers). For example, heat pumps are more efficient than gas boilers as they can produce up to 4kW of heat for every 1kW of electricity consumed. That’s 4 times as much energy!
3. You want to switch from natural gas to renewable energy
Transitioning away from fossil fuels is a home improvement that is better for the environment. It has become easier to lead a more sustainable lifestyle as low-carbon heating options become increasingly more accessible. Research has shown that compared to standard boilers, green energy is more efficient, produces fewer carbon emissions and can last a lot longer.
4. Your boiler is damaged: leaking, broken valves, or corrosion
A leak doesn’t always mean it’s time for a replacement boiler. However, it does mean there’s an internal issue, such as a broken valve or seal letting air in. Despite modern boilers being designed to prevent corrosion, if a leak continues to expose the iron to air without being repaired by an engineer, then it can cause corrosion or structural damage.
If the corrosion is found on the casing, it can sometimes be fixed. But if corrosion is found inside the tank that’s causing the leak, it is best to replace it with a new boiler installation. In those cases, if the repair and maintenance costs for your damaged boiler are more than buying a new one, it is worth considering getting a replacement boiler.
5. You don’t have enough hot water for your use
If your current boiler cannot supply enough hot water for your regular household use, then your current boiler may not have enough power to effectively heat your home. If you’re looking to upgrade your boiler, you should know that having a larger boiler than you need results in wasted energy. This increases both your bills and your carbon footprint.
6. Making unusual noises
Boilers will naturally produce some sound, however, any sounds that are particularly loud or unfamiliar may mean serious malfunctions and safety concerns. While many of the unusual sounds can be fixed by a boiler engineer, it may be a signal that your boiler is wearing out. The source of the sound must be properly diagnosed and fixed before worsening.
One of the most common sounds a boiler may make is a clicking/tapping sound usually caused by a boiler struggling to ignite. You may also hear your boiler make a banging sound, also known as kettling. Kettling is when build-ups of scale deposits restrict the water flow in the heat exchange causing it to become hot and start steaming.
7. Smelling odour
A sulphurous, eggy odour coming from your boiler may be indicative of an internal problem, such as a gas leak. In the most dangerous case, your boiler could be emitting poisonous gas into your home. Carbon monoxide is notoriously difficult to detect because it is odourless and tasteless, but chemicals are added to give it a distinctive smell for detecting leaks.
If you smell a bad odour, immediately turn off your boiler and call a technician immediately. If this problem is recurring, it may be time to consider transitioning from natural gas to heat your home. However, the issue may very well be with another part of the central heating system, so it is ideal to have a technician come to confirm before getting a new boiler system.

How Much Does A New Boiler Cost In The UK?
The average cost of new boilers in the UK can range anywhere from £500 to £21,000. The range is so large because there are a lot of factors to consider, like what type of new boiler system you buy.
Boilers are a 15-year investment that can help you save money in the long term. The trick to getting the proper one is by choosing an efficient boiler that fits your own demands and suits the structure of your house.
So when buying a replacement boiler, keep in mind the boiler type, fuel type, boiler size (output rating), and installation costs. Some questions you should start asking yourself are:
- What are my heating and hot water demands?
- Do I want to get the same kind of boiler that I am replacing?
- Do I want to switch to a low carbon heating option?
- Do I want it in the same location?
- Do I want to use the same fuel?
Boiler Type
The total replacement cost of your gas boiler will depend on the heating system you choose. If you’re looking to replace your current boiler and bought it before 2005, you should know that condensing boiler regulations introduced in 2005 prohibit new installations of non-condensing boilers.
Condensing boilers are encouraged because they not only emit fewer carbon emissions, but also burn fuel up to 30% more efficiently. Switching to a condensing boiler can save you up to £310 annually on gas bills.
The table below shows the cost range for some of the most common boiler types in the UK (excluding installation costs). Depending on the size of your house and your heating demands, the price of a new boiler may vary.
Boiler Types | Fuel Type | Price Bands |
---|---|---|
Combi Boiler | Gas, oil, electric or LPG | £500 - £2,000 |
System Boiler | Gas, oil or electric | £1000 - £2,500 |
Conventional Boiler | Gas or oil | £500 - £2,750 |
If you’re looking for a more eco-friendly option to boilers, there are many alternatives to gas boilers. Although renewable heating systems are usually more expensive than gas boilers, they may heat your house for twice as long. A boiler’s average lifespan is 10-15 years, whereas heat pumps and solar thermal panels can last up to 25 years. That’s a single renewable heating system in the lifetime of two gas boiler replacements!
The good news for you is that the government offers heat pump grants which can help you save as much as £5000! And to top it all, since April 2022, you don’t have to pay VAT on energy efficient measures, like heat pumps, for the next five years.
The current global situation has shed light on the fact that now is without a doubt one of the best times to invest in clean renewable energy. By investing in the future, you're protecting your household from the market instability and rising gas prices in the UK.
Alternatives to Gas Boilers | Potential Cost |
---|---|
Oil Boiler | £1,000 – £3,000 |
LPG Boiler | £500 – £2,500 |
Electric Boiler | £650 – £4,500 |
Biomass Boiler | £4,000 – £21,000 |
Air Source Heat Pump | £4,000 – £18,000 |
Ground Source Heat Pump | £20,000 – £35,000 |
Solar Thermal System | £3,000 – £5,000 |
Infrared Heating Panels | £150 – £500 per panel |
Hybrid Heating System | £5,000 – £10,000 |
Installing a heat pump for your house might be an excellent alternative if you want to transition from a gas boiler to a more eco-friendly solution. Nonetheless, it is a significant investment. Depending on your property and installation, air source heat pumps might cost anywhere from £8,000 to £18,000.
We understand that this is a significant home improvement, so if you still want a more environmentally-friendly gas boiler replacement, we recommend that you consider a cheaper alternative until a heat pump becomes more financially feasible. An electric boiler, for example, is a good way to lessen your carbon impact.
Fuel Type
You may also end up spending more on your energy bill depending on the fuel you burn. The most common fuel types are gas, oil, electricity, and biomass. Depending on where you live in the UK, you may be restricted by what gas type you can use.
In addition to fuel price, the amount of carbon emissions you produce per kilowatt is also something to consider. 85% of homes in the UK run on gas, however, replacing your boiler is a good opportunity to switch to a more renewable energy source, such as electricity or biomass.
Fuel Type | Gas | Oil | LPG | Electricity | Wood Pellet |
---|---|---|---|---|---|
pence/kW | 7.4 | 11.8 | 15.5 | 28.3 | 9.9 |
kg CO2/kW | 0.22 | 0.30 | 0.24 | 0.23 | 0.05 |
Output Rating
You will also need to consider the size of your boiler before you replace it. The size of a boiler is measured by its output rating in kilowatts (kW). The higher the output rating, the more powerful the boiler. An output rating that’s too low won’t be able to meet the demand, while an output rating that’s too high means you could be paying too much.
The larger your home, the more kilowatts your boiler will need, and thus the more it will cost to run. Because of how combi, system, and conventional boilers work, they require different output ratings depending on the house size.
Number of Bathrooms | Number of Radiators | Combi Boiler Recommended Size | System or Conventional Boiler Recommended Size |
---|---|---|---|
1/kW | 10 | 24-27 kW | 10-18 kW |
2 | 15 | 27-32 kW | 18-26 kW |
3+ | 20 | 34-42 kW | 27-40 kW |
What Are The Installation Costs For A Boiler Replacement?
On average, the installation cost of new boilers in the UK is £500-£1,000. However, the installation cost from a boiler engineer can be more depending on the complexity of the installation and where you live.
For instance, a like-for-like boiler swap (e.g. old combi boiler for a new one) is a more straightforward and budget-friendly boiler replacement. In comparison, if you wanted to switch to a new gas boiler system, it can be twice as expensive. Especially if your home does not already have a running gas line.
Additional Conversion Costs | Price Band |
---|---|
Chemical cleanse of existing system | £50 - £150 |
Upgraded heating controls | £50 - £300 |
New boiler filter, including installation | £150 - £250 |
Restructuring pipe work | £250 - £5,000 |
Gas safe registration fee and labour cost | £354 + VAT |
Old boiler and water cylinder removal | £600 - £1000 |
Keep in mind that the price ranges we provide are our best estimates. Naturally, as you would with other investments, getting quotes from multiple installers is a crucial part of the process. Quotes from verified boiler installers can help you make sure your investment is done safely and for the best price. Fortunately, we’re here if you would like to compare quotes from up to four installers. Let us help you with this part of the research process.
Is There A Government Grant Which Encourages Gas Boiler Replacements?
Homes in the UK can receive financial assistance for the purchase and installation of gas boiler replacements through government incentives for renewable and energy-efficient solutions like solar panels and heat pumps. Grants like this exist because the UK government aims to have net-zero carbon emissions by 2050.
Therefore, the government encourages homeowners to transition away from gas boilers. One of the grants that does this is the Boiler Upgrade Scheme. In this scheme, homes in the UK can receive government grants of £5000 to buy low-carbon heating systems like air source heat pumps or biomass boilers, and £6000 for ground source heat pumps.
5 Reasons Why Gas Boiler Replacement Is Future Proof
1. Renewables are the cornerstone of the energy transition
In 2019, the UK announced their plans to have net-zero greenhouse emissions by 2050 in an effort to curb climate change. As we head towards this ambitious goal, our energy consumption needs to change.
2. How we currently heat our homes is a large threat to the climate
One of the biggest barriers to achieving the 2050 net-zero emissions target is how we heat our homes. Natural gas boilers heat more than 85% of homes across the UK. Every year, they produce 58.5 million tonnes of carbon dioxide. In comparison, the 27 million cars in the UK produce 56 million tonnes annually.
This makes how we heat our homes a bigger threat to the climate than cars. So, the conversation is no longer just about switching to electric vehicles, but also about how you can switch to low-carbon heating.
3. Gas boilers can no longer compete
The transition away from gas boilers is an inevitable move as the environmental crisis and recently soaring gas prices expose the real inefficiencies of gas boilers. Gas boilers lose as much as 30% of the energy they produce in a year.
We now have alternative ways to supply energy with gas that have the potential to be 99% energy efficient. The most common alternatives include heat pumps, electric boilers, and biomass boilers.
4. Gas has been considered a “transition fuel” towards clean energy
Many countries moved from coal to gas as a less expensive and less environmentally damaging way to transition towards more renewable energy. But high gas prices and market volatility have made natural gas an expensive option. The idea of gas as a transition fuel continues to decrease in relevance as renewable energy becomes more accessible on a larger scale.
So, moving on without gas boilers is becoming more of a reality as regulations, such as the gas Boiler Ban and the Boiler Upgrade Scheme, are introduced. There are also grant schemes that help people transition from older heating systems to newer, more environmentally friendly systems. Replacing your gas boiler now prepares your home for the future as environmental, political, and economic pressure to transition increases.
5. Being environmentally friendly is becoming more accessible
While climate change mitigation is a strong motivator for moving away from fossil fuel-based electricity generation, it is far from the only one. Thanks to technological advancements and economies of scale, renewable energy is becoming the most cost-effective method of energy generation.
You can see that renewable energy continues to become more accessible financially and infrastructurally as its percentage of total energy continues to climb year after year.
Find Local Engineers For Boiler Replacements
Getting a boiler is a purchase you make only every 10 to 15 years. Needless to say, there are a lot of things to consider before getting a replacement boiler installed. We would recommend seeking the advice of a Gas Safe registered installer.
They can make sure you’re getting the right solution for your home’s unique circumstances. Fortunately, we can help you find installers near you, who can give you free, no-obligation quotes.
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